Gender dimorphism in body composition abnormalities in acromegaly: males are more affected than females

Background: Acromegaly changes body composition (BC), but long-term gender differences have not been reported. Objective: To evaluate BC in active and controlled acromegalic patients. Design and methods: Clinical and biochemical variables and BC (by dual-energy X-ray absorptiometry) were evaluated in 60 acromegalic patients (19 active, 41 controlled) and 105 controls, matched for age and gender. Results: Acromegalic males (nZ24) had more total mass (89G13 vs 76.5G15.3 kg, P!0.001), lean body mass (LBM; 64.6G8.7 vs 56.4G5.8 kg, P!0.001), and bone mineral content (BMC; 2.9G0.5 vs 2.6G0.3 kg, P!0.05) than controls (nZ33). Controlled male patients (nZ14) had more total mass (89G14.7 vs 76.5G15.3 kg, P!0.05) and a trend to have more LBM (61.8G9.4 vs 56.4G5.8 kg, PZ0.065) than controls. Only in active disease was a decrease in fat mass (FM) observed, compared with controlled patients and controls (males: 19.5G5.3 vs 27G6.2 and 25.9G4%, P!0.001; females: 30.3G 6.7 vs 37.1G5.8 and 36.5G6.6%, P!0.01). In females, no further differences were observed. No differences in BMC were found between eugonadal and hypogonadal acromegalic patients, but in hypogonadal females, acromegaly appeared to prevent the BMC loss seen in hypogonadal postmenopausal controls. GH and IGF1 levels were negatively correlated with FM (males, P!0.05; females, P!0.001), but in the regression analysis GH was a predictor of FM only in women. Conclusions: Control of acromegaly reverts decreased FM in both genders; only in males more total mass and a trend for more LBM persist. The anabolic effect of GH on bone reverted in cured males, but persisted in females and appeared to override the bone loss of menopause.